Soanian

[7][8] Debates still go on today regarding the exact period occupied by the culture due to artifacts often found in non-datable surface contexts.

[7] The anthropology and archaeology team led by Helmut de Terra and Thomas Thomson Paterson first discovered and named this culture.

[7] Soanian artifacts were manufactured on quartzite pebbles, cobbles, and occasionally on boulders, all derived from various fluvial sources on the Siwalik landscape.

Soanian assemblages generally comprise choppers, discoids, scrapers, cores, and flake-type tools, all occurring in varying typo-technological frequencies at different sites.

The emergence of Soanian tools has been tied to the local development of boulder conglomerate formation through prehistoric tectonic processes that created a convenient transporting system for raw materials.

[7][12] According to this view, Soanian technological culture evolved throughout three broad intervals during the Middle Pleistocene period from circa 774,000 to 129,000 years ago.

[11][8] Scholars of this view believe the technological culture potentially belonged to the ancient hominid group: homo erectus.

[7] Scholars began to question the three-interval theory when both early Soanian and Late-Soanians tools started to be found together along the same undatable sites.

[7] To continue, the Soan river 'terraces' observed by de Terra and Paterson were later discovered to be erosional features rather than terrace sequences that would suggest the prehistorical timing of the artifacts.

[7] Early human civilizations emerged from antecedent agricultural communities of hills bouldering the Indus alluvial plain.

[8] From 1.6 million years ago onwards, the existing boulder conglomerate formation saw more changes that further contributed to easy raw materials access for local ancient humans.

Further tectonic movements and erosion saw the Siwalik fluvial courses altered –developing more complex river systems and deposits that carried and collected sediments.

[8] Scholars of the single interval period argue Soanian tools were developed due to the movement of the Harappan culture.

[7] This period has been viewed as a process of deurbanization of the Harappan culture, where they began to decrease in size, turning into smaller village-type settlements.

[8] Understanding of the technological development of Soanian tools has been limited due to most sites rarely comprising more than a few dozen artifacts.

[7] However, due to climate change during the mid-Holocene epoch, many original settlements collapsed in search of water and have been reduced in size.

[7] The Western Sub-Himalaya and the Siwalik Hills first caught the interest of archaeologists and palaeontologists in the early 1800s when the Miocene age fossil apes were uncovered.

[8] De Terra and Paterson deemed the artifacts found in Siwalik belonged to a specific technological culture named “Soanian”.

[8] This method entails carefully surveying and recording artifacts along vast regions, seeking to understand the spatial relationship each lithic culture has with one another.

[8] Hundreds of edged pebble tools were discovered at Adiala and Khasala Kalan, about 16 km (9.9 mi) from Rawalpindi terrace on the river's bend.

Soan River near Chakri.
Example of a boulder conglomerate - not of Siwalik region.
Unifacial chopper.
Neolithic lithic scraper.